(a) Field of the Invention
The present invention relates to a heat- and fireproof duct, and more particularly, to a duct to contain electrical and communication wires and the like, wherein damage or partial or complete destruction of the latter are prevented in case a fire erupts or there is excessive heat in their vicinity. Whenever the word fire appears throughout the description and claims, this should ipso facto include heat and fire, i.e. fireproof should mean heat- and fireproof.
(b) Description of Prior Art
It is well known that when there is a fire or excessive heat in a building, a lot of destruction takes place and sometimes there is only some damage done. It is also of common knowledge that if the electrical and communication wires are destroyed or damaged, this may have severe consequences due to the impossibility of establishing any kind of communication with persons in the building and because electrical appliances which are sometimes essential cease to operate.
In U.S. Pat. Nos. 3,779,179 and 5,109,779 as well as in Canadian Patent No. 987,542, there are disclosed fire insulated partitions which are made of a double wall and wherein water circulation is initiated within the inner space defined by the double wall as soon as a fire starts in the vicinity of the double partition thereby providing fire insulation in a space surrounded by fire insulated partitions. However, although this system has a lot of merit, it may not be adequate to protect the electrical and communication wiring or the like. In many cases, it may not be practical or possible to provide a building with the above type of double partition, so that additional protection should be envisaged for the wiring system.